Complementary determining regions

Here the hapten (Scheme 2) is a 13-diketone, which incorporates structural features of both reactants - ketone donor and aldehyde acceptor (see below, Scheme 3) - in the aldol reaction of interest. In favorable cases the hapten reacts with the primary amino-group of a lysine residue in the complementary-determining region of an antibody to form a Schiffbase 5, which readily tautomerises to the more stable vinylogous amide 6. 

Lantto J, Ohlin M, Functional consequences of insertions and deletions in the complementary-determining regions of human antibodies, J. Biol. Chem., 277 45108-14, 2002. 

J. Higo, V. Collura, J. Gamier, Development of an extended simulated annealing method application to the modeling of complementary determining regions of immunoglobulins. Biopolymers, 32 (1992) 33. 

Abbreviations. CDR = complementary determining region EBV = Epstein-Barr virus NMR = nuclear magnetic resonance QSAR = quantitative structure-activity relationship SAR = structure-activity relationship. 

The general twofold symmetrical structure of an immunoglobulin G. There are three constant sections on the heavy chains (CHI, CH2, CH3) and one variable section (VH). Each light chain has a constant (CL) and a variable (VL) section. Antigens are bound by the hypervariahle CDRs (complementary determining regions). 

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